Threats / Microsoft / CVE-2011-2005
CVE-2011-2005
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Microsoft Ancillary Function Driver (afd.sys) vulnerability
Microsoft's Ancillary Function Driver (afd.sys) fails to properly validate user-mode input in kernel-mode operations, allowing local attackers to escalate privileges through a crafted application.
Verdict
Today item — known-exploited.
A local privilege escalation vulnerability in Windows kernel driver afd.sys due to insufficient input validation. Attackers with local access can exploit this to gain elevated system privileges. Active exploitation in the wild has been documented.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
2 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-28).
Probability (EPSS)
EPSS 0.31761 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Ancillary Function Driver (afd.sys). Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-264 Permissions/Privileges/Access Control — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious application that sends specially crafted input to the Ancillary Function Driver.
Business
An attacker gains local code execution capability on the affected system.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I exploit the lack of input validation in afd.sys to transition from user mode to kernel mode with elevated privileges.
Business
The attacker obtains SYSTEM-level access, bypassing all user-account security boundaries.
3
Lateral reach — past segmentation narrative 3
Attacker
I use kernel-level access to install persistent malware, disable security controls, or pivot to other systems.
Business
Complete system compromise occurs, enabling data theft, lateral movement, and long-term persistence within the network.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05